Article coated with water-repellent film, liquid composition for coating with water-repellent film, and process for producing article coated with water-repellent film

ABSTRACT

There are provided articles coated with high-performance water-repellent films with high hardness that can withstand outdoor use, which are water-repellent film-coated articles that comprise a substrate and a water-repellent film composed mainly of silicon oxide and having a water-repellent group coated on the surface of the substrate, and are characterized by containing at least one type of metal oxide selected from the group consisting of magnesium oxide, calcium oxide, strontium oxide and boron oxide, as well as a process for preparation of such water-repellent film-coated articles at a high rate of productivity and a coating liquid composition for preparation of such water-repellent film-coated articles.

This application is a continuation of international applicationPCT/JP00/05081, filed Aug. 1, 2000, published as WO 01/09266 A1 on Feb.8, 2001.

TECHNICAL FIELD

The present invention relates to articles provided with awater-repellent film coating formed integrally with an primary oxidefilm on the surface of a substrate made of glass, ceramic, plastic,metal or the like, to a water-repellent film-coating composition and toa process for preparation of water-repellent film-coated articles.

BACKGROUND ART

The following techniques for formation of highly durable water-repellentfilms on the surfaces of glass plates and other substrates at a highrate of productivity are known, which involve formation of a single filmon a substrate using a mixed solution of a primary layer component and awater-repellent component which gives a primary layer and awater-repellent layer.

In Japanese Unexamined Patent Publication No. 4-338137 there isdisclosed a water-repellent glass characterized by applying of asolution comprising a mixture of a silicon alkoxide or a substitutedsilicon alkoxide wherein a portion of the alkoxyl groups are substitutedwith fluoroalkyl groups, an alcohol, water and an acid (or base) onto aglass substrate surface and sintering.

In Japanese Unexamined Patent Publication No. 8-239653 there aredisclosed water-repellent articles treated with a composition comprisinga mixture of a perfluoroalkylalkylsilane and a thoroughly hydrolyzablesilane (for example, tetrachlorosilane) dissolved in a solvent,preferably a non-aqueous solvent.

In Japanese Unexamined Patent Publication No. 11-71682 there aredisclosed water-repellent film-coated articles treated with acomposition comprising a chlorosilyl group-containing compound and afluoroalkyl group-containing silane compound dissolved in analcohol-based solvent.

In these conventional techniques, the final water-repellent article hasbeen obtained by applying the coating solution onto the surface of theglass plate or the other substrate and then sintering at a temperatureof 100-250° C. which is lower than the decomposition temperature of thefluoroalkyl groups (250-300° C.), or simply drying at ordinarytemperature. The films obtained by these techniques are known as sol-gelwater-repellent films and are obtained through a process whereby ahydrolyzable silane compound and a silane compound with awater-repellent group are hydrolyzed in a solution, subjected todehydration/condensation reaction and then coated and dried on asubstrate; in the sol-gel film, however, the solvent progressivelyevaporates as oxide bonds are formed, and therefore fine pores arepresent in the film when it is dried at 400° C. or below, so that thefilm does not have high hardness. In order to avoid the pores forincreased film hardness, it has been essential to accomplish sinteringat 500-600° C. However, heating at such high temperatures results indecomposition of the fluoroalkyl groups, making it impossible to achievethe desired water repellency. Consequently, water-repellent filmsobtained by the aforementioned technique of sintering at 250° C. orbelow, while being composed mainly of oxides, have not had the highhardness as oxides and ceramics which is achieved by, for example, meltmethods.

When such water-repellent film-coated articles are used outdoors, forexample, their exposure to such conditions as blown sand readily resultsin damage to the film surface, thus impairing the water-repellentproperty. The water-repellent film can also be damaged or peeled whenthe surface is wiped with a cloth or the like to remove attached dust,dirt or sand. Even in the absence of attached dust, etc., abrasion witha cloth or brush made of hard fibers (such as surface wiping ofautomobile window glass with a wiper, for example) forms small nicks andfurther promote deterioration of the water-repellent film.

It is an object of the present invention, which has been accomplished inlight of these problems, to provide articles coated withhigh-performance water-repellent films having high hardness that canwithstand outdoor use, a process for preparation of such water-repellentfilm-coated articles at a high rate of productivity, and a coatingliquid composition for preparation of such water-repellent film-coatedarticles.

DISCLOSURE OF THE INVENTION

As a result of much diligent research by the present inventors aimed atovercoming the aforementioned problems, it has been discovered that byproviding a primary oxide film with two or more components includingSiO₂ and at least one type selected from among MgO, CaO, SrO and B₂O₃ ina water-repellent film-coated article having a primary oxide layer and awater-repellent layer integrally formed by a single coating treatment,the hardness of the water-repellent film with the integrally formedprimary layer and water-repellent layer is drastically improved.

In other words, the present invention relates to a water-repellentfilm-coated article comprising a substrate and a water-repellent filmcomposed mainly of silicon oxide and having a water-repellent groupcoated on the surface of the substrate, the water-repellent film-coatedarticle being characterized in that the water-repellent film contains atleast one type of metal oxide selected from the group consisting ofmagnesium oxide, calcium oxide, strontium oxide and boron oxide.

For formation of oxide films by a sol-gel method it is common to use asilicon alkoxide as the starting material, and this is because thereactivity of silicon alkoxides readily gives a uniform, transparentfilm by a milder reaction than with alkoxides of elements other thansilicon. However since, as mentioned above, the solvent progressivelyevaporates as bonds (siloxane bonds) are formed between the Si (silicon)and O (oxygen) by dehydration/condensation reaction in the sol-gelmethod, a porous silica film is obtained wherein fine pores are presentin the film. Since the Si and O bonds are covalent bonds and Si and Obond with a high bonding energy, when siloxane bonds form a somewhatthree-dimensional structure at the solvent volatilization stage,contraction of the structure is suppressed even with subsequent furtherdehydration/condensation reaction, such that a volatilized portion ofthe solvent and the alcohol produced by the dehydration/condensationreaction remains as fine pores, with silanol or unreacted alkoxyl groupspresent in the fine pores. The hardness of the porous silica film is notvery high because of its porosity. When the film is heated at atemperature of 500° C. or above, the fine pores in the film disappearproducing a non-porous silica film with high hardness, but it isdifficult to form an integral film with high hardness containingsubstances that decompose at the heating temperature.

According to the invention, the strong ionic nature of magnesium (Mg),calcium (Ca) and strontium (Sr) is utilized: they are dissolved in thecoating solution to be copresent with the thoroughly hydrolyzable silanecompound, such as a silicon alkoxide, and exist in an ionic state in thesolution even at the solvent volatilization stage. Because Mg, Ca and Srare divalent, they react with silanol, eventually bonding with twooxygen atoms in the film interior as shown in Equation (1), and formingan “O⁻ ⁺M⁺ ⁻O” bond which has a freer bonding orientation than an“Si—O—Si” bond, to thereby fill in the gaps of the siloxane skeleton.

When simply dried at normal temperature, for example, this film hasabout the same hardness as if a silica component alone was used, butheating at a temperature of 50-300° C. contracts the siloxane bonds byaction of the Mg (or Ca or Sr), and this eliminates pores and results ina film with high hardness and high durability comparable to inorganicglass prepared by a melt method. That is, while heating at a temperatureof 500° C. or above is necessary to eliminate the pores of a simpleporous silica film, the porous silica-based film of the invention whichcontains MgO, CaO or SrO can be rendered pore-free at a temperature of200° C. or more below that temperature. Furthermore, since the film isheated at a temperature lower than the decomposition temperature of thewater-repellent groups such as fluoroalkyl groups or alkyl groups (300°C. or higher), the fluoroalkyl groups or alkyl groups contained in thecoating solution reside on the film surface without decomposition, thusproviding excellent water repellency and durability. When only a silicacomponent with water-repellent groups is present, the film hasinsufficient hardness and low durability with heat hardening at 300° C.or below, and heating at a temperature of 500° C. or above is necessaryto eliminate the film pores and increase the film hardness, which inturn sacrifices the high water repellency.

Addition of an oxide of boron (B) to the silica also provides a lowtemperature hardening property and gives a pore-free film with highhardness by heating at a temperature of 300° C. or below, as withaddition of Mg, Ca or Sr described above. While it is not yet fullyunderstood why B exhibits a similar effect as Mg, Ca and Sr, it isthought to be attributable to a change in the configuration of oxygendue to the heating immediately after coating.

If the content of magnesium oxide, calcium oxide, strontium oxide andboron oxide in the water-repellent film is too low the low temperaturehardening effect will not be obtained, while if it is too high theoxides will segregate to a non-uniform condition, thus lowering the filmhardness; the water-repellent film therefore preferably contains siliconoxide, magnesium oxide, calcium oxide, strontium oxide and boron oxidein the following proportions, based on SiO₂, MgO, CaO, SrO and BO_(3/2),respectively:

silicon oxide at 70-99%, and

at least one type of metal oxide selected from the group consisting ofmagnesium oxide, calcium oxide, strontium oxide and boron oxide at atotal of 1-30%,

in terms of mole percent; the water-repellent film also preferablycontains silicon oxide, magnesium oxide, calcium oxide, boron oxide andzirconium oxide in the following proportions, based on SiO₂, MgO, CaO,BO_(3/2) and ZrO₂, respectively:

silicon oxide at 70-98%,

magnesium oxide and/or calcium oxide at 1-29%,

and boron oxide and/or zirconium oxide at 1-29%, in terms of molepercent.

Certain combinations among these give superior low temperature hardeningproperties. Specifically, they are the four combinations Si—Mg—B,Si—Ca—B, Si—Mg—Zr and Si—Ca—Zr. These sol-gel oxide films harden by, forexample, heating at 200-250° C. for films with a film thickness of about150 nm and heating at about 100° C. for films with a film thickness of afew dozen nm or less, giving water-repellent films with high hardness.

Thus, according to the present invention an oxide film of two or morecomponents including silicon oxide and at least one type selected fromamong magnesium oxide, calcium oxide, strontium oxide and boron oxide asessential components is used as the primary oxide layer to allowelimination of pores from the primary oxide film at below thedecomposition temperature of the water-repellent layer. Water-repellentfilm-coated articles obtained thereby have high hardness or durabilitythat has not been possible in the past with water-repellent film-coatedarticles with integrally formed primary oxide layers and water-repellentlayers by a single coating treatment.

The low temperature hardening property of the water-repellent film ofthe invention is not impaired even when a transition metal element orthe like is further introduced into the silica film for the purpose ofadding another function in addition to the water-repellent function,such as control of the refractive index of the film or control of thevisible light transmittance. In other words, by including a metalelement exhibiting a desired function along with the Mg, Ca, Sr or B itis possible to obtain a multifunctional film having very high hardnesseven with heating at a temperature of 300° C. or below, while alsohaving both water-repellent and other functions. For example, additionof cobalt oxide, iron oxide, nickel oxide or copper oxide will impartcoloring to the water-repellent film.

When the water-repellent film of the invention contains zirconium oxide,it may include as other components cobalt oxide, iron oxide, nickeloxide, copper oxide, aluminum oxide, gallium oxide, indium oxide,scandium oxide, yttrium oxide, lanthanum oxide, cerium oxide and zincoxide at a total of 0.5-5% in terms of mole percent, based on CoO,FeO_(3/2), NiO₂, CuO, AlO_(3/2), GaO_(3/2), InO_(3/2), ScO_(3/2),YO_(3/2), LaO_(3/2), CeO_(3/2) and ZnO.

When the water-repellent film of the invention contains no zirconiumoxide, it may include as other components cobalt oxide, iron oxide,nickel oxide, copper oxide, zirconium oxide, aluminum oxide, galliumoxide, indium oxide, scandium oxide, yttrium oxide, lanthanum oxide,cerium oxide and zinc oxide at a total of 0.5-5% in terms of molepercent, based on CoO, FeO_(3/2), NiO₂, CuO, ZrO₂, AlO_(3/2), GaO_(3/2),InO_(3/2), ScO_(3/2), YO_(3/2), LaO_(3/2), CeO_(3/2) and ZnO.

In either case, addition of these components at a total in excess of 5mole percent may produce an undesirable appearance, such as film peelingor film whitening.

If the thickness of the water-repellent film is too great the filmhardness will tend to be lower, and if it is too small the filmdurability will tend to be lower. The thickness of the water-repellentfilm is therefore preferably 5-200 nm, more preferably 5-100 nm and evenmore preferably 5-50 nm. The water-repellent film preferably containsthe water-repellent groups, for example alkyl groups or fluoroalkylgroups, at 0.01-20 wt %. The water-repellent groups are present at ahigh density on the outer surface of the water-repellent film.

The present invention also provides a water-repellent film-coatingcomposition containing

(A) a thoroughly hydrolyzable silane compound,

(B) a silane compound with a water-repellent group,

(C) an acid and

(D) at least one metal compound selected from the group consisting ofmagnesium, calcium, strontium and boron.

The thoroughly hydrolyzable silane compound (A) according to theinvention is not particularly limited, and tetraalkoxysilanes such astetramethoxysilane, tetraethoxysilane, tetrapropoxysilane andtetrabutoxysilane, as well as tetrachlorosilane, tetraacyloxysilane andtetraisocyanatesilane may be mentioned. Tetraalkoxysilanes are preferredfor use among these because of their relative ease of handling. Amongtetraalkoxysilanes, those of relatively low molecular weight, forexample tetraalkoxysilanes comprising alkoxyl groups of 3 or fewercarbon atoms, are preferred for use because they readily give densefilms. Also, polymers of these tetraalkoxysilanes, with averagepolymerization degrees of 5 or lower, are preferred for use.

The silane compound with a water-repellent group (B) according to theinvention is a silane compound with one, two or more water-repellentgroups (alkyl groups, fluoroalkyl groups, etc.) in the molecule, andthere may be mentioned silane compounds which are the aforementionedsilane compounds (A) a portion of which is substituted with an alkylgroup and/or fluoroalkyl group.

Examples of alkyl group-containing silane compounds include alkylgroup-containing chlorosilanes such as

CH₃(CH₂)₃₀SiCl₃, CH₃(CH₂)₂₀SiCl₃,

CH₃(CH₂)₁₈SiCl₃, CH₃(CH₂)₁₆SiCl₃,

CH₃(CH₂)₁₄SiCl₃, CH₃(CH₂)₁₂SiCl₃,

CH₃(CH₂)₁₀SiCl₃, CH₃(CH₂)₉SiCl₃,

CH₃(CH₂)₈SiCl₃, CH₃(CH₂)₇SiCl₃,

CH₃(CH₂)₆SiCl₃, CH₃(CH₂)₅SiCl₃,

CH₃(CH₂)₄SiCl₃, CH₃(CH₂)₃SiCl₃,

CH₃(CH₂)₂SiCl₃, CH₃CH₂SiCl₃,

(CH₃CH₂)₂SiCl₂, (CH₃CH₂)₃SiCl,

CH₃SiCl₃, (CH₃)₂SiCl₂, (CH₃)₃SiCl;

alkyl group-containing alkoxysilanes such as

CH₃(CH₂)₃₀Si(OCH₃)₃, CH₃(CH₂)₂₀Si(OCH₃)₃,

CH₃(CH₂)₁₈Si(OCH₃)₃, CH₃(CH₂)₁₆Si(OCH₃)₃,

CH₃(CH₂)₁₄Si(OCH₃)₃, CH₃(CH₂)₁₂Si(OCH₃)₃,

CH₃(CH₂)₁₀Si(OCH₃)₃, CH₃(CH₂)₉Si(OCH₃)₃,

CH₃(CH₂)₈Si(OCH₃)₃, CH₃(CH₂)₇Si(OCH₃)₃,

CH₃(CH₂)₆Si(OCH₃)₃, CH₃(CH₂)₅Si(OCH₃)₃,

CH₃(CH₂)₄Si(OCH₃)₃, CH₃(CH₂)₃Si(OCH₃)₃,

CH₃(CH₂)₂Si(OCH₃)₃, CH₃CH₂Si(OCH₃)₃,

(CH₃CH₂)₂Si(OCH₃)₂, (CH₃CH₂)₃SiOCH₃,

CH₃Si(OCH₃)₃, (CH₃)₂Si(OCH₃)₂, (CH₃)₃SiOCH₃,

CH₃(CH₂)₃₀Si(OC₂H₅)₃, CH₃(CH₂)₂₀Si(OC₂H₅)₃,

CH₃(CH₂)₁₈Si(OC₂H₅)₃, CH₃(CH₂)₁₆Si(OC₂H₅)₃,

CH₃(CH₂)₁₄Si(OC₂H)₃, CH₃(CH₂)₁₂Si(OC₂H₅)₃,

CH₃(CH₂)₁₀Si(OC₂H₅)₃, CH₃(CH₂)₉Si(OC₂H₅)₃,

CH₃(CH₂)₈Si(OC₂H₅)₃, CH₃(CH₂)₇Si(OC₂H₅)₃,

CH₃(CH₂)₆Si(OC₂H₅)₃, CH₃(CH₂)₅Si(OC₂H₅)₃,

CH₃(CH₂)₄Si(OC₂H₅)₃, CH₃(CH₂)₃Si(OC₂H₅)₃,

CH₃(CH₂)₂Si(OC₂H₅)₃, CH₃CH₂Si(OC₂H₅)₃,

(CH₃CH₂)₂Si(OC₂H₅)₂, (CH₃CH₂)₃SiOC₂H₅,

CH₃Si(OC₂H₅)₃, (CH₃)₂Si(OC₂H₅)₂, (CH₃)₃SiOC₂H₅;

alkyl group-containing acyloxysilanes such as

CH₃(CH₂)₃₀Si(OCOCH₃)₃, CH₃(CH₂)₂₀Si(OCOCH₃)₃,

CH₃(CH₂)₁₈Si(OCOCH₃)₃, CH₃(CH₂)₁₆Si(OCOCH₃)₃,

CH₃(CH₂)₁₄Si(OCOCH₃)₃, CH₃(CH₂)₁₂Si(OCOCH₃)₃,

CH₃(CH₂)₁₀Si(OCOCH₃)₃, CH₃(CH₂)₉Si(OCOCH₃)₃,

CH₃(CH₂)₈Si(OCOCH₃)₃, CH₃(CH₂)₇Si(OCOCH₃)₃,

CH₃(CH₂)₆Si(OCOCH₃)₃, CH₃(CH₂)₅Si(OCOCH₃)₃,

CH₃(CH₂)₄Si(OCOCH₃)₃, CH₃(CH₂)₃Si(OCOCH₃)₃,

CH₃(CH₂)₂Si(OCOCH₃)₃, CH₃CH₂Si(OCOCH₃)₃,

(CH₃CH₂)₂Si(OCOCH₃)₂, (CH₃CH₂)₃SiOCOCH₃,

CH₃Si(OCOCH₃)₃, (CH₃)₂Si(OCOCH₃)₂,

(CH₃)₃SiOCOCH₃;

and alkyl group-containing isocyanatesilanes such as

CH₃(CH₂)₃₀Si(NCO)₃, CH₃(CH₂)₂₀Si(NCO)₃,

CH₃(CH₂)₁₈Si(NCO)₃, CH₃(CH₂)₁₆Si(NCO)₃,

CH₃(CH₂)₁₄Si(NCO)₃, CH₃(CH₂)₁₂Si(NCO)₃,

CH₃(CH₂)₁₀Si(NCO)₃, CH₃(CH₂)₉Si(NCO)₃,

CH₃(CH₂)₈Si(NCO)₃, CH₃(CH₂)₇Si(NCO)₃,

CH₃(CH₂)₆Si(NCO)₃, CH₃(CH₂)₅Si(NCO)₃,

CH₃(CH₂)₄Si(NCO)₃, CH₃(CH₂)₃Si(NCO)₃,

CH₃(CH₂)₂Si(NCO)₃, CH₃CH₂Si(NCO)₃,

(CH₃CH₂)₂Si(NCO)₂, (CH₃CH₂)₃SiNCO,

CH₃Si(NCO)₃, (CH₃)₂Si(NCO)₂,

(CH₃)₃SiNCO.

Among these alkyl group-containing silane compounds it is preferred touse chlorosilanes, alkoxysilanes, acyloxysilanes and isocyanatesilanescontaining alkyl groups of 8 or more carbon atoms, such as thefollowing.

Octyltrimethyoxysilane CH₃(CH₂)₇Si(OCH₃)₃,

octyltrichlorosilane CH₃(CH₂)₇Si(Cl)₃,

nonyltrimethoxysilane CH₃(CH₂)₈Si(OCH₃)₃,

nonyltrichlorosilane CH₃(CH₂)₈Si(Cl)₃,

decyltrimethoxysilane CH₃(CH₂)₉Si(OCH₃)₃,

decyltrichlorosilane CH₃(CH₂)₉Si(Cl)₃,

undecyltrimethoxysilane CH₃(CH₂)₁₀Si(OCH₃)₃,

undecyltrichlorosilane CH₃(CH₂)₁₀Si(Cl)₃,

dodecyltrimethoxysilane CH₃(CH₂)₁₁Si(OCH₃)₃,

dodecyltrichlorosilane CH₃(CH₂)₁₁Si(Cl)₃.

Examples of fluoroalkyl group-containing silane compounds includefluoroalkyl group-containing trichlorosilanes such as

CF₃(CF₂)₁₁(CH₂)₂SiC₃,

CF₃(CF₂)₁₀(CH₂)₂Si(Cl)₃,

CF₃(CF₂)₉(CH₂)₂SiCl₃,

CF₃(CF₂)₈(CH₂)₂SiCl₃,

CF₃(CF₂)₇(CH₂)₂SiCl₃,

CF₃(CF₂)₆(CH₂)₂SiCl₃,

CF₃(CF₂)₅(CH₂)₂SiCl₃,

CF₃(CF₂)₄(CH₂)₂SiCl₃,

CF₃(CF₂)₃(CH₂)₂SiCl₃,

CF₃(CF₂)₂(CH₂)₂SiCl₃,

CF₃CF₂(CH₂)₂SiCl₃,

CF₃(CH₂)₂SiCl₃;

fluoroalkyl group-containing trialkoxysilanes such as

CF₃(CF₂)₁₁(CH₂)₂Si(OCH₃)₃,

CF₃(CF₂)₁₀(CH₂)₂Si(OCH₃)₃,

CF₃(CF₂)₉(CH₂)₂Si(OCH₃)₃,

CF₃(CF₂)₈(CH₂)₂Si(OCH₃)₃,

CF₃(CF₂)₇(CH₂)₂Si(OCH₃)₃,

CF₃(CF₂)₆(CH₂)₂Si(OCH₃)₃,

CF₃(CF₂)₅(CH₂)₂Si(OCH₃)₃,

CF₃(CF₂)₄(CH₂)₂Si(OCH₃)₃,

CF₃(CF₂)₃(CH₂)₂Si(OCH₃)₃,

CF₃(CF₂)₂(CH₂)₂Si(OCH₃)₃,

CF₃CF₂(CH₂)₂Si(OCH₃)₃,

CF₃(CH₂)₂Si(OCH₃)₃,

CF₃(CF₂)₁₁(CH₂)₂Si(OC₂H₅)₃,

CF₃(CF₂)₁₀(CH₂)₂Si(OC₂H₅)₃,

CF₃(CF₂)₉(CH₂)₂Si(OC₂H₅)₃,

CF₃(CF₂)₈(CH₂)₂Si(OC₂H₅)₃,

CF₃(CF₂)₇(CH₂)₂Si(OC₂H₅)₃,

CF₃(CF₂)₆(CH₂)₂Si(OC₂H₅)₃,

CF₃(CF₂)₅(CH₂)₂Si(OC₂H₅)₃,

CF₃(CF₂)₄(CH₂)₂Si(OC₂H₅)₃,

CF₃(CF₂)₃(CH₂)₂Si(OC₂H₅)₃,

CF₃(CF₂)₂(CH₂)₂Si(OC₂H₅)₃,

CF₃CF₂(CH₂)₂Si(OC₂H₅)₃,

CF₃(CH₂)₂Si(OC₂H₅)₃;

fluoroalkyl group-containing triacyloxysilanes such as

CF₃(CF₂)₁₁(CH₂)₂Si(OCOCH₃)₃,

CF₃(CF₂)₁₀(CH₂)₂Si(OCOCH₃)₃,

CF₃(CF₂)₉(CH₂)₂Si(OCOCH₃)₃,

CF₃(CF₂)₈(CH₂)₂Si(OCOCH₃)₃,

CF₃(CF₂)₇(CH₂)₂Si(OCOCH₃)₃,

CF₃(CF₂)₆(CH₂)₂Si(OCOCH₃)₃,

CF₃(CF₂)₅(CH₂)₂Si(OCOCH₃)₃,

CF₃(CF₂)₄(CH₂)₂Si(OCOCH₃)₃,

CF₃(CF₂)₃(CH₂)₂Si(OCOCH₃)₃,

CF₃(CF₂)₂(CH₂)₂Si(OCOCH₃)₃,

CF₃CF₂(CH₂)₂Si(OCOCH₃)₃,

CF₃(CH₂)₂Si(OCOCH₃)₃;

and fluoroalkyl group-containing triisocyanatesilanes such as

CF₃(CF₂)₁₁(CH₂)₂Si(NCO)₃,

CF₃(CF₂)₁₀(CH₂)₂Si(NCO)₃,

CF₃(CF₂)₉(CH₂)₂Si(NCO)₃,

CF₃(CF₂)₈(CH₂)₂Si(NCO)₃,

CF₃(CF₂)₇(CH₂)₂Si(NCO)₃,

CF₃(CF₂)₆(CH₂)₂Si(NCO)₃,

CF₃(CF₂)₅(CH₂)₂Si(NCO)₃,

CF₃(CF₂)₄(CH₂)₂Si(NCO)₃,

CF₃(CF₂)₃(CH₂)₂Si(NCO)₃,

CF₃(CF₂)₂(CH₂)₂Si(NCO)₃,

CF₃CF₂(CH₂)₂Si(NCO)₃,

CF₃(CH₂)₂Si(NCO)₃.

Among these fluoroalkyl group-containing silane compounds there arepreferred trichlorosilanes, trialkoxysilanes and triisocyanatesilanescontaining fluoroalkyl groups with 10 or more fluorine atoms, of whichCF₃(CF₂)₇(CH₂)₂Si(OCH₃)₃ (heptadecafluorodecyl trimethoxysilane) andCF₃(CF₂)₇(CH₂)₂SiCl₃ (heptadecafluorodecyl trichlorosilane) areparticularly preferred.

The acid (C) according to the invention is preferably a volatile acidsuch as hydrochloric acid, hydrofluoric acid, nitric acid, acetic acid,formic acid, trifluoroacetic acid or the like from the standpoint ofvolatilization by drying at ordinary temperature without remaining inthe film, and hydrochloric acid is particularly preferred among thesebecause of its high degree of electrolytic dissociation andvolatilization and its relative safety during handling.

At least one type of metal compounds selected from the group consistingof magnesium, calcium, strontium and boron (D) according to theinvention may be any chlorides, oxychlorides, oxides, hydroxides,nitrates, oxynitrates, etc. of the aforementioned metals, so long asthey undergo simple electrolytic dissociation to dissolve in water oralcohol. Among these, it is particularly preferred to use chlorides,oxychlorides, nitrates and oxynitrates.

Specific examples for component (D) include MgCl₂, Mg(NO₃)₂, CaCl₂,Ca(NO₃)₂, SrCl₂, Sr(NO₃)₂ and H₃BO₃.

The zirconium oxide is not an essential component, but including it withthe magnesium oxide or calcium oxide increases the low temperaturehardening property, and therefore a zirconium compound, for example achloride, oxychloride, oxide, hydroxide, nitrate or oxynitrate, whichundergoes simple electrolytic dissociation to dissolve in water oralcohol, may be included in the water-repellent film-coatingcomposition. Specific examples of such compounds include ZrOCl₂ andZrO(NO₃)₂.

As an additional component (component (E)) there may be added to thewater-repellent film-coating composition at least one metal compoundselected from the group consisting of cobalt, iron, nickel, copper,aluminum, gallium, indium, scandium, yttrium, lanthanum, cerium andzinc, such as a chloride, oxychloride, oxide, hydroxide, nitrate oroxynitrate of one or more of these metals, as the starting material forcobalt oxide, iron oxide, nickel oxide, copper oxide, aluminum oxide,gallium oxide, indium oxide, scandium oxide, yttrium oxide, lanthanumoxide, cerium oxide and zinc oxide, for the purpose of imparting theaforementioned functions of control of the refractive index of the filmor control of the visible light transmittance. Any of these compoundsare suitable so long as they dissociate in water or alcohol, and thosethat undergo simple electrolytic dissociation are especially preferred.In other words, it preferably decomposes without producing oxideprecipitation, etc., and is present in the coating solution in an ionstate.

Specific examples of the aforementioned component (E) include AlCl₃,GaCl₃, InCl₃, ScCl₃, YCl₃, LaCl₃, CeCl₃, CoCl₂, ZnCl₂, Al(NO₃)₃,Ga(NO₃)₃, In(NO₃)₃, Sc(NO₃)₃, Y(NO₃)₃, La(NO₃)₃, Ce(NO₃)₃, Co(NO₃)₂,Zn(NO₃)₂.

The water-repellent film-coating composition preferably contains thesilane compound (A) at 0.01-2 wt % based on silica, the silane compound(B) at 0.00001-0.15 wt % based on silica, the acid at 0.001-3 N, waterat 0-5 wt %, the compound (D) at a molar ratio of 0.01-0.4 with respectto the silane compound (A), and the component (E) at a molar ratio of0-0.4 with respect to the silane compound (A).

The solvent for the water-repellent film-coating composition is notparticularly limited, but hydrocarbons such as hexane, toluene andcyclohexane, halogenated hydrocarbons such as methyl chloride, carbontetrachloride and trichloroethylene, ketones such as acetone and methylethyl ketone, nitrogen-containing compounds such as diethylamine, esterssuch as ethyl acetate, and alcohols may be used. Preferred for use amongthese are alcohol-based solvents, examples of which include methanol,ethanol, 1-propanol, 2-propanol, butyl alcohol, amyl alcohol and thelike among which straight-chain saturated monohydric alcohols of 3 orfewer carbon atoms, such as methanol, ethanol, 1-propanol and 2-propanolare even more preferred for use because of their high volatilizationrates at ordinary temperature.

These alcohols may also contain water at from 0 wt % to 50 wt %.Commercially available high-grade alcohols usually contain water at 0.2wt % or more, and according to the invention they are preferably used toavoid cost-raising treatments such as dewatering treatment. For additionof the metal starting materials, even when the metal compounds are addedafter first being dissolved in water, the amount of water in the finalwater-repellent film-coating composition may be 50 wt % or less withrespect to the amount of solvent. The amount of water is preferably notgreater than 50 wt % because this will prevent a uniform, transparentfilm from being formed.

A preferred water-repellent film-coating composition according to theinvention contains

(A) a thoroughly hydrolyzable silane compound or its hydrolysate at0.01-2 wt % (based on silica),

(B) a silane compound with a water-repellent group at 0.00001-0.15 wt %(based on silica),

(C) an acid at 0.001-3 N,

(D) at least one type of metal compound selected from the groupconsisting of magnesium, calcium, strontium and boron at a molar ratioof 0.01-0.4 based on MgO, CaO, SrO and BO_(3/2), with respect to thesilane compound (A),

(E) at least one type of metal compound selected from the groupconsisting of cobalt, iron, nickel, copper, zirconium, aluminum,gallium, indium, scandium, yttrium, lanthanum, cerium and zinc at amolar ratio of 0-0.4 based on CoO, FeO_(3/2), NiO₂, CuO, AlO_(3/2),GaO_(3/2), InO_(3/2), ScO_(3/2), YO_(3/2), LaO_(3/2), CeO_(3/2) and ZnO,with respect to the silane compound (A),

(F) water at 0-20 wt % and

(G) an alcohol constituting the remainder.

An even more preferred water-repellent film-coating composition contains

(A) a thoroughly hydrolyzable silane compound or its hydrolysate at0.01-2 wt % (based on silica),

(B) a silane compound with a water-repellent group at 0.00001-0.15 wt %(based on silica),

(C) an acid at 0.001-3 N,

(D-1) a magnesium and/or calcium compound at a molar ratio of 0.01-0.4based on MgO and CaO, with respect to the silane compound (A) (based onSiO₂),

(D-2) a boron and/or zirconium compound at a molar ratio of 0.01-0.4based on BO_(3/2) and ZrO₂, with respect to the silane compound (A)(based on SiO₂),

(E) at least one type of metal compound selected from the groupconsisting of cobalt, iron, nickel, copper, aluminum, gallium, indium,scandium, yttrium, lanthanum, cerium and zinc at a molar ratio of 0-0.4based on CoO, FeO_(3/2), Nia₂, CuO, AlO_(3/2), GaO_(3/2), InO_(3/2),ScO_(3/2), YO_(3/2), LaO_(3/2), CeO_(3/2) and ZnO, with respect to thesilane compound (A) (based on SiO₂),

(F) water at 0-20 wt % and

(G) an alcohol constituting the remainder.

The method of coating the water-repellent film-coating composition ofthe invention is not particularly limited, but preferably the substrateis evenly wetted with the coating solution composition and thenstationed for drying to hardness. This allows formation of a highlyoriented water-repellent layer as the fluoroalkyl groups and alkylgroups collect on the liquid surface during volatilization of thesolvent. Here, the stationing is sufficient so long as the coatingsolution applied to the substrate is not disturbed, and the substratemay even be gently moved in a parallel direction during the application.

Specific examples of coating methods include dip coating, flow coating,curtain coating, spin coating, spray coating, bar coating, roll coating,brush coating and the like.

The drying according to the invention is carried out in an atmosphere atroom temperature or a temperature of 300° C. or below, and preferably at40% or lower relative humidity. The coated state of the highly orientedsurface is therefore maintained without decomposition of the integrallycoated alkyl groups or fluoroalkyl groups. As a result it is possible toobtain a water-repellent film with a low temperature hardening propertyas well as excellent water-repellent performance including dropletroll-over properties and excellent durability due to its high hardness.Because of the low heating temperature, even when an alkali component ispresent in the substrate there is low diffusion thereof in thewater-repellent film, thus preventing reduction in durability of thewater-repellent property due the alkali.

As substrates for the invention there may be mentioned transparent andnon-transparent plates, bars and other various forms of glass, ceramic,plastic or metal. When few hydrophilic groups are present on the surfaceof the substrate, it is preferred to pretreat the surface with anoxygen-containing plasma or corona atmosphere for hydrophilic treatment,or to irradiate the substrate surface with ultraviolet rays of awavelength near 200-300 nm in an oxygen-containing atmosphere forhydrophilic treatment, followed by surface treatment.

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiments of the present invention will now be explained in detail byway of examples.

EXAMPLE 1

To 97.68 g of ethanol (moisture content: 0.35 wt %) there were added0.02 g of heptadecafluorodecyl trimethoxysilane(CF₃(CF₂)₇(CH₂)₂Si(OCH₃)₃, product of Shinetsu Silicone), 0.24 g oftetraethoxysilane (Si(OCH₂CH₃)₄₁ product of Shinetsu Silicone), 0.0586 gof magnesium chloride hexahydrate (product of Kanto Kagaku) and 2 g ofconcentrated hydrochloric acid (35 wt %, product of Kanto Kagaku) whilestirring, to obtain a coating solution. Table 1 shows the types andamounts (molar ratios) of the tetraethoxysilane (TEOS),heptadecafluorodecyl trimethoxysilane (FAS), and magnesium or calciumstarting materials in the coating solution. The total weight of the TEOSand magnesium starting material (or calcium starting material) in thecoating solution (wt % based on SiO₂, MgO and CaO) was 0.08 wt %. Thiswater-repellent coating solution was applied to the surface of a washedsoda lime silicate glass-composed glass substrate (3.4 mm×150×150 mm) at30% humidity and room temperature (20° C.) using a flow coating method,and then dried at room temperature for about one minute to obtain awater-repellent glass plate. The composition of the water-repellent filmwas as shown in Table 1. The value for the water-repellent groups isgiven with respect to 100 mole percent as the total for all of theoxides, and it was 2.4 mole percent based on FAS (likewise for thefollowing examples and comparative examples). The proportion ofwater-repellent groups (the CF₃(CF₂)₇(CH₂)₂-portion) was 16 wt % withrespect to the total weight of the film.

The water contact angle for the resulting water-repellent glass platewas measured using a contact angle instrument (CA-DT, product of KyowaSurfactant Chemistry, KK.), as the static contact angle for a waterdroplet of 2 mg weight. A larger value for the contact angle indicatesbetter static water repellency.

As an index for the roll-over performance of water droplets on thesurface of the water-repellent glass plate, a 5-mm diameter waterdroplet was placed on the horizontally positioned water-repellent glassplate surface, and then the water-repellent glass plate was slowlytilted until the water droplet placed on the surface first began toroll, at which point the tilt angle (critical tilt angle) of the glassplate was measured. A smaller critical tilt angle indicates betterdynamic water repellency, and for example, better dispersion of raindroplets adhering to the front glass window of a moving automobile, thuscausing less blockage of the field of vision of the driver.

Evaluation of the hardness of the water-repellent film was carried outaccording to the abrasion test specified by JIS R 3212. Specifically, acommercially available Taber abrasion test was conducted with 1000abrasion passes at a weight of 500 g, with measurement of the haze valuebefore and after the abrasion test and optical microscope observation ofany film peeling before and after the abrasion test. The film waschecked for peeling after the abrasion test, and any film that exhibitedno peeling was also measured for haze value.

Table 2 shows the film thickness, contact angle, critical tilt angle,haze value before and after the Taber abrasion test and film peelingbefore and after the abrasion test for the water-repellent film. Theresulting film had an especially low critical tilt angle of 4°, and thiswas believed to indicate that the Mg ions had filled the gaps in thesilica porous body, thus improving the smoothness of the film.

EXAMPLES 2-10

Water-repellent glass was obtained in the same manner as Example 1,except that the metal atom starting materials and addition amounts inthe coating solution of Example 1 were changed to those shown inTable 1. The compositions of the water-repellent films were as shown inTable 1. The results of measurement in the same manner as Example 1 areshown in Table 2. The total weight of the TEOS and magnesium startingmaterial (or calcium or strontium starting material) in the coatingsolutions (wt % based on SiO₂, MgO, CaO or SrO) was 0.08 wt %.

The films obtained in the same manner as Example 1 had very low criticaltilt angles of 4°, and this was believed to indicate that the Mg, Ca andSr ions had filled the gaps in the silica porous bodies, thus improvingthe smoothness of the films.

COMPARATIVE EXAMPLE 1

To 85.3 g of ethanol there were added 40 g of tetraethoxysilane and 1.92g of heptadecafluorodecyl trimethoxysilane, and after 20 minutes ofstirring, 16.6 g of water and 20.8 g of 0.1 N hydrochloric acid wereadded and the mixture was stirred for 2 hours, placed in a sealedcontainer and allowed to stand at 25° C. for 24 hours to obtain awater-repellent coating solution. The composition of the water-repellentcoating solution is shown in Table 1. A washed glass plate was immersedin the water-repellent coating solution and lowered for coating, andafter drying it was fired at 250° C. for one hour to obtain awater-repellent glass plate. The composition of the water-repellent filmwas as shown in Table 1. The TEOS weight in the coating solution (basedon SiO₂) was 6.5 wt %.

As shown in Table 2, the resulting water-repellent glass plate had aninitial critical tilt angle of 180, which was large compared to Examples1-7, and poor water droplet roll-over. When Comparative Example 1 wasdried at room temperature instead of at 250° C. for one hour, the waterdroplet roll-over was unchanged but the film underwent considerablescratching by mere light rubbing with a cloth.

COMPARATIVE EXAMPLE 2

To 97.68 g of ethanol (moisture content: 0.35 wt %) there were added0.02 g of heptadecafluorodecyl trimethoxysilane(CF₃(CF₂)₇(CH₂)₂Si(OCH₃)₃, product of Shinetsu Silicone), 0.3 g oftetraethoxysilane (Si(OCH₂CH₃)₄, product of Shinetsu Silicone) and 2 gof concentrated hydrochloric acid (35 wt %, product of Kanto Kagaku)while stirring, to obtain a coating solution. A water-repellent glassplate was otherwise obtained in the same manner as Example 1. Thecomposition of the water-repellent film was as shown in Table 1. Theweight of the TEOS in the coating solution (based on SiO₂) was 0.08 wt%.

As shown in Table 2, the resulting water-repellent glass plate had aninitial critical tilt angle of 80, which was large compared to Examples1-7, and inferior droplet roll-over. Even when Comparative Example 2 washeated at 200° C. for 30 minutes instead of drying at room temperature,peeling of the film occurred after the abrasion test.

TABLE 1 Component Water- ratio Film composition repellent Starting(molar (mole %) groups material ratio) SiO₂ MgO Cao SrO (based on FAS)Examples 1 TEOS/MgCl₂ · 6H₂O 80/20 80 20 0 0 2.4 2 TEOS/Mg(NO₃)₂ · 6H₂O80/20 80 20 0 0 2.4 3 TEOS/Mg(OH)₂ · 6H₂O 80/20 80 20 0 0 2.4 4 TEOS/MgO80/20 80 20 0 0 2.4 5 TEOS/CaCl₂ 80/20 80 0 20 0 2.4 6 TEOS/Ca(NO₃)₂ ·4H₂O 80/20 80 0 20 0 2.4 7 TEOS/Ca(OH)₂ · 4H₂O 80/20 80 0 20 0 2.4 8TEOS/SrCl₂ 80/20 80 0 0 20 2.4 9 TEOS/Sr(NO₃)₂ 80/20 80 0 0 20 2.4 10 TEOS/Sr(OH)₂ · 8H₂O 80/20 80 0 0 20 2.4 Comparative Examples 1 TEOS 1000 0 0 1.8 2 TEOS 100 0 0 0 2.4

TABLE 2 Film Critical Haze value Haze value (%) thick- Contact tilt (%)before after abrasion ness angle angle abrasion test/film (nm) (degree)(degree) test peeling Example 1 30 108 4 0.0 peeling Example 2 30 108 40.0 peeling Example 3 30 108 4 0.0 peeling Example 4 30 108 4 0.0peeling Example 5 30 108 4 0.0 peeling Example 6 30 108 4 0.0 peelingExample 7 30 108 4 0.0 peeling Example 8 30 108 4 0.0 peeling Example 930 108 4 0.0 peeling Example 10 30 108 4 0.0 peeling Comparative 40 10015 0.0 peeling Example 1 Comparative 40 108 7 0.0 peeling Example 2

EXAMPLES 11-32

Water-repellent glass was obtained in the same manner as Example 1,except that the metal atom starting materials and addition amounts inthe coating solution of Example 1 and the drying temperature and timeafter coating were changed to those shown in Table 3. The compositionsof the water-repellent films were as shown in Tables 4 and 5. Theresults of measurement in the same manner as Example 1 are shown inTable 6. The total content of the TEOS and different metal oxidestarting materials in the coating solutions (wt % based on SiO₂, MgO,CaO, B₂O₃, Al₂O₃, Ga₂O₃, In₂O₃, Sc₂O₃, Y₂O₃, La₂O₃, Ce₂O₃, CoO, ZnO,ZrO₂) was 0.08 wt %.

The resulting films had small initial critical tilt angles of 5-8°, andwere very hard water-repellent films with no film peeling even afterTaber abrasion.

EXAMPLES 33-36

Water-repellent glass was obtained in the same manner as Example 1,except that the metal atom starting materials and addition amounts inthe coating solution of Example 1 and the drying temperature and timeafter coating were changed to those shown in Table 7. The compositionsof the water-repellent films were as shown in Table 8. The results ofmeasurement in the same manner as Example 1 are shown in Table 9. Thetotal content of the TEOS and different metal oxide starting materialsin the coating solutions (wt % based on SiO₂, MgO, CaO and B₂O₃) was0.08 wt %.

The resulting films had small initial critical tilt angles of 5-7°, andwere very hard water-repellent films with no film peeling even afterTaber abrasion.

EXAMPLES 37-40

Water-repellent glass was obtained in the same manner as Example 1,except that heptadecafluorodecyl trimethoxysilane was changed tododecyltrimethoxysilane (CH₃(CH₂)₉Si(OCH₃)₃, product of Tokyo Kasei,hereunder also referred to as “AS”), and the metal atom startingmaterials and addition amounts in the coating solution of Example 1 andthe drying temperature and time after coating were changed to thoseshown in Table 7. The compositions of the water-repellent films were asshown in Table 8. The results of measurement in the same manner asExample 1 are shown in Table 9. The total content of the TEOS anddifferent metal oxide starting materials in the coating solutions (wt %based on SiO₂, MgO, CaO, B₂O₃ and ZrO₂) was 0.08 wt %.

The resulting films had small critical tilt angles, though slightlylarger than Example 1, and were hard water-repellent films with no filmpeeling even after Taber abrasion.

EXAMPLES 41-60

Water-repellent glass was obtained in the same manner as Example 1,except that the metal atom starting materials and addition amounts inthe coating solution of Example 1 and the drying temperature and timeafter coating were changed to those shown in Table 10. The compositionsof the water-repellent films were as shown in Table 11. The results ofmeasurement in the same manner as Example 1 are shown in Table 12. Thetotal content of the TEOS and different metal oxide starting materialsin the coating solutions (wt % based on SiO₂, MgO, CaO, B₂O₃₁, Al₂O₃,CoO, Fe₂O₃, NiO and CuO) was 0.08 wt %.

The resulting films had small critical tilt angles, though slightlylarger than Example 1, and were hard water-repellent films with no filmpeeling even after Taber abrasion.

Also, coloration due to the added transition metals was found inExamples 43-50 and 53-60, so that the resulting water-repellent filmswere very hard and colored.

COMPARATIVE EXAMPLES 3 and 4

Water-repellent glass was obtained in the same manner as Example 1,except that the metal atom starting materials and addition amounts inthe coating solution of Example 1 and the drying temperature and timeafter coating were changed to those shown in Table 13. The results ofmeasurement in the same manner as Example 1 are shown in Table 14. Thetotal content of the TEOS and different metal oxide starting materialsin the coating solutions (wt % based on SiO₂, La₂O₃ and CoO) was 0.08 wt%.

Comparative Examples 3 and 4 both had inferior outer appearances of thefilms, and their hardnesses were such that the films completely peeledoff after the Taber test.

TABLE 3 Com- ponent Ex- ratio Heating am- (molar temperature/ pleStarting material ratio) time 11 TEOS/MgCl₂ · 6H₂O/H₃BO₃ 98/1/1 100°C.-30 min. 12 TEOS/CaCl₂/H₃BO₃ 98/1/1 100° C.-30 min. 13 TEOS/MgCl₂ ·6H₂O/AlCl₃ · 6H₂O 97/2/1 200° C.-30 min. 14 TEOS/CaCl₂/AlCl₃ · 6H₂O97/2/1 200° C.-30 min. 15 TEOS/MgCl₂6H₂O/GaCl₃ 97/2/1 200° C.-30 min. 16TEOS/CaCl₂/GaCl₃ 97/2/1 200° C.-30 min. 17 TEOS/MgCl₂6H₂O/InCl₃ · 4H₂O97/2/1 200° C.-30 min. 18 TEOS/CaCl₂/InCl₃ · 4H₂O 97/2/1 200° C.-30 min.19 TEOS/MgCl₂6H₂O/ScCl₃ · 6H₂O 97/2/1 200° C.-30 min. 20TEOS/CaCl₂/ScCl₃ · 6H₂O 97/2/1 200° C.-30 min. 21 TEOS/MgCl₂6H₂O/YCl₃ ·6H₂O 97/2/1 200° C.-30 min. 22 TEOS/CaCl₂/YCl₃ · 6H₂O 97/2/1 200° C.-30min. 23 TEOS/MgCl₂6H₂O/LaCl₃ · 7H₂O 97/2/1 200° C.-30 min. 24TEOS/CaCl₂/LaCl₃ · 7H₂O 97/2/1 200° C.-30 min. 25 TEOS/MgCl₂6H₂O/CeCl₃ ·7H₂O 97/2/1 200° C.-30 min. 26 TEOS/CaCl₂/CeCl₃ · 7H₂O 97/2/1 200° C.-30min. 27 TEOS/MgCl₂ · 6H₂O/CoCl₂ · 6H₂O 97/2/1 200° C.-30 min. 28TEOS/CaCl₂/CoCl₂ · 6H₂O 97/2/1 200° C.-30 min. 29 TEOS/MgCl₂ ·6H₂O/ZnCl₂ 97/2/1 200° C.-30 min. 30 TEOS/CaCl₂ · ZnCl₂ 97/2/1 200°C.-30 min. 31 TEOS/MgCl₂ · 6H₂O/ZrOCl₂ · 8H₂O 98/1/1 100° C.-30 min. 32TEOS/CaCl₂/ZrOCl₂ · 8H₂O 98/1/1 100° C.-30 min.

TABLE 4 Film composition (mole %) Water-repellent groups Example SiO₂MgO CaO B₂O₃ Al₂O₃ Ga₂O₃ In₂O₃ Sc₂O₃ (based on FAS) 11 98.5 1.0 0 0.5 00 0 0 2.4 12 98.5 0 1.0 0.5 0 0 0 0 2.4 13 97.5 2.0 0 0 0.5 0 0 0 2.4 1497.5 0 2.0 0 0.5 0 0 0 2.4 15 97.5 2.0 0 0 0 0.5 0 0 2.4 16 97.5 0 2.0 00 0.5 0 0 2.4 17 97.5 2.0 0 0 0 0 0.5 0 2.4 18 97.5 0 2.0 0 0 0 0.5 02.4 19 97.5 2.0 0 0 0 0 0 0.5 2.4 20 97.5 0 0 0 0 0 0 0.5 2.4

TABLE 5 Film composition (mole %) Water-repellent groups Example SiO₂MgO CaO ZrO₂ Y₂O₃ La₂O₃ Ce₂O₃ CoO ZnO (based on FAS) 21 97.5 2.0 0 0 0.50 0 0 0 2.4 22 97.5 0 2.0 0 0.5 0 0 0 0 2.4 23 97.5 2.0 0 0 0 0.5 0 0 02.4 24 97.5 0 2.0 0 0 0.5 0 0 0 2.4 25 97.0 2.0 0 0 0 0 1.0 0 0 2.4 2697.0 0 2.0 0 0 0 1.0 0 0 2.4 27 97.0 2.0 0 0 0 0 0 1.0 0 2.4 28 97.0 02.0 0 0 0 0 1.0 0 2.4 29 97.0 2.0 0 0 0 0 0 0 1.0 2.4 30 97.0 0 2.0 0 00 0 0 1.0 2.4 31 98.0 1.0 0 1.0 0 0 0 0 0 2.4 32 98.0 0 2.0 1.0 0 0 0 00 2.4

TABLE 6 Critical Haze value Haze value (%) Film Contact tilt (%) beforeafter abrasion thickness angle angle abrasion test/film Example (nm)(degree) (degree) test peeling 11 30 109 6 0.0 1.2 12 30 110 6 0.1 0.913 30 108 7 0.2 1.1 14 30 107 8 0.1 1.3 15 30 107 7 0.1 1.1 16 30 108 70.1 1.2 17 30 109 7 0.2 1.2 18 30 108 8 0.1 1.4 19 30 107 8 0.1 1.1 2030 108 7 0.0 1.1 21 30 107 7 0.1 1.3 22 30 107 8 0.0 1.1 23 30 107 8 0.01.2 24 30 107 8 0.1 1.4 25 30 108 8 0.0 1.2 26 30 107 7 0.2 1.3 27 30107 8 0.1 1.2 28 30 108 7 0.1 1.4 29 30 108 8 0.1 1.2 30 30 107 8 0.01.3 31 30 109 5 0.0 0.9 32 30 109 6 0.0 1.0

TABLE 7 Com- ponent Ex- ratio Heating am- (molar temperature/ pleStarting material ratio) time 33 TEOS/MgCl₂ · 6H₂O 80/20 200° C.-30 min.34 TEOS/CaCl₂ 80/20 200° C.-30 min. 35 TEOS/H₃BO₃ 95/5 200° C.-30 min.36 TEOS/H₃BO₃ 99/1 200° C.-30 min. 37 TEOS/MgCl₂ · 6H₂O/H₃BO₃ 98/1/1200° C.-30 min. 38 TEOS/CaCl₂/H₃BO₃ 98/1/1 200° C.-30 min. 39 TEOS/MgCl₂· 6H₂O/ZrOCl₂ · 8H₂O 98/1/1 200° C.-30 min. 40 TEOS/CaCl₂/ZrOCl₂ · 8H₂O98/1/1 200° C.-30 min.

TABLE 8 Film composition (mole %) Water-repellent groups Example SiO₂MgO CaO B₂O₃ ZrO₂ (based on FAS or AS) 33 80 20 0 0 0 0.036 34 80 0 20 00 0.036 35 95 0 0 5 0 0.036 36 99 0 0 1 0 0.036 37 98.5 1 0 0.5 0 0.03638 98.5 0 1 0.5 0 0.036 39 98.0 1 0 0 1 0.036 40 98.0 0 1 0 1 0.036

TABLE 9 Critical Haze value Haze value (%) Film Contact tilt (%) beforeafter abrasion thickness angle angle abrasion test/film Example (nm)(degree) (degree) test peeling 33 30 109 6 0.0 1.1 34 30 109 7 0.0 1.235 30 109 6 0.0 1.1 36 30 109 5 0.0 1.0 37 30 109 6 0.0 1.0 38 30 109 60.0 1.0 39 30 109 5 0.0 0.9 40 30 109 6 0.0 1.0

TABLE 10 Starting material Heating Example (component ratio (molarratio)) temperature/time 41 TEOS/MgCl₂ · 6H₂O/H₃BO₃/AlCl₃ ·6H₂O(96/2/1/1) 200° C.-30 min. 42 TEOS/CaCl₂/H₃BO₃/AlCl₃ ·6H₂O(96/2/1/1) 200° C.-30 min. 43 TEOS/MgCl₂ · 6H₂O/H₃BO₃/CoCl₂ ·6H₂O(93/2/1/4) 200° C.-30 min. 44 TEOS/CaCl₂/H₃BO₃/CoCl₂ ·6H₂O(93/2/1/4) 200° C.-30 min. 45 TEOS/MgCl₂ · 6H₂O/H₃BO₃/FeCl₂(93/2/1/4) 200° C.-30 min. 46 TEOS/CaCl₂/H₃BO₃/FeCl₂ (93/2/1/4) 200°C.-30 min. 47 TEOS/MgCl₂ · 6H₂O/H₃BO₃/NiCl₂ · 6H₂O(93/2/1/4) 200° C.-30min. 48 TEOS/CaCl₂/H₃BO₃/NiCl₂ · 6H₂O(93/2/1/4) 200° C.-30 min. 49TEOS/MgCl₂ · 6H₂O/H₃BO₃/CuCl₂ · 4H₂O(93/2/1/4) 200° C.-30 min. 50TEOS/CaCl₂/H₃BO₃/CuCl₂ · 4H₂O(93/2/1/4) 200° C.-30 min. 51 TEOS/MgCl₂ ·6H₂O/ZrO(NO₃)₂ · 8H₂O/AlCl₃ · 6H₂O(96/2/1/1) 200° C.-30 min. 52TEOS/CaCl₂/ZrO(NO₃)₂ · 8H₂O/AlCl₃ · 6H₂O(96/2/1/1) 200° C.-30 min. 53TEOS/MgCl₂ · 6H₂O/ZrOCl₂ · 8H₂O/CoCl₂ · 6H₂O(96/2/1/4) 200° C.-30 min.54 TEOS/CaCl₂/ZrOCl₂ · 8H₂O/CoCl₂ · 6H₂O(93/2/1/4) 200° C.-30 min. 55TEOS/MgCl₂ · 6H₂O/ZrOCl₂ · 8H₂O/FeCl₂ (93/2/1/4) 200° C.-30 min. 56TEOS/CaCl₂/ZrOCl₂ · 8H₂O/FeCl₂ (93/2/1/4) 200° C.-30 min. 57 TEOS/MgCl₂· 6H₂O/ZrOCl₂ · 8H₂O/NiCl₂ · 6H₂O(93/2/1/4) 200° C.-30 min. 58TEOS/CaCl₂/ZrOCl₂ · 8H₂O/NiCl₂ · 6H₂O(93/2/1/4) 200° C.-30 min. 59TEOS/MgCl₂ · 6H₂O/ZrOCl₂ · 8H₂O/CuCl₂ · 4H₂O(93/2/1/4) 200° C.-30 min.60 TEOS/CaCl₂/ZrOCl₂ · 8H₂O/CuCl₂ · 4H₂O(93/2/1/4) 200° C.-30 min.

TABLE 11 Film composition (mole %) Example SiO₂ MgO CaO B₂O₃ ZrO₂ Al₂O₃CoO Fe₂O₃ NiO CuO 41 97.0 2.0 0 0.5 0 0.5 0 0 0 0 42 97.0 0 2.0 0.5 00.5 0 0 0 0 43 93.5 2.0 0 0.5 0 0 4.0 0 0 0 44 93.5 0 2.0 0.5 0 0 4.0 00 0 45 95.4 2.1 0 0.5 0 0 0 2.1 0 0 46 95.4 0 2.1 0.5 0 0 0 2.1 0 0 4793.5 2.0 0 0.5 0 0 0 0 4.0 0 48 93.5 0 2.0 0.5 0 0 0 0 4.0 0 49 93.5 2.00 0.5 0 0 0 0 0 4.0 50 93.5 0 2.0 0.5 0 0 0 0 0 4.0 51 96.5 2.0 0 0 1.00.5 0 0 0 0 52 96.5 0 2.0 0 1.0 0.5 0 0 0 0 53 96.0 2.0 0 0 1.0 0 4.0 00 0 54 96.0 0 2.0 0 1.0 0 4.0 0 0 0 55 94.9 2.0 0 0 1.0 0 0 2.0 0 0 5694.9 0 2.0 0 1.0 0 0 2.0 0 0 57 93.0 2.0 0 0 1.0 0 0 0 4.0 0 58 93.0 02.0 0 1.0 0 0 0 4.0 0 59 93.0 2.0 0 0 1.0 0 0 0 0 4.0 60 93.0 0 2.0 01.0 0 0 0 0 4.0

TABLE 12 Critical Haze value Haze value (%) Film Contact tilt (%) beforeafter abrasion thickness angle angle abrasion test/film Example (nm)(degree) (degree) test peeling 41 30 109 6 0.0 1.2 42 30 110 6 0.1 0.943 30 108 7 0.2 1.1 44 30 107 8 0.1 1.3 45 30 107 7 0.1 1.1 46 30 108 70.1 1.2 47 30 109 7 0.2 1.2 48 30 108 8 0.1 1.4 49 30 107 8 0.1 1.1 5030 108 7 0.0 1.1 51 30 107 7 0.1 1.3 52 30 107 8 0.0 1.1 53 30 107 8 0.01.2 54 30 107 8 0.1 1.4 55 30 108 8 0.0 1.2 56 30 107 7 0.2 1.3 57 30107 8 0.1 1.2 58 30 108 7 0.1 1.4 59 30 108 8 0.1 1.2 60 30 107 8 0.01.3

TABLE 13 Comparative Starting material Heating Example (molar ratio)temperature/time 3 TEOS/CoCl₂ · 6H₂O(98/2) 250° C.-30 min. 4 TEOS/LaCl₃· 7H₂O(98/2) 250° C.-30 min.

TABLE 14 Critical Haze value (%) Compara- Film Contact tilt Haze valueafter abrasion tive thickness angle angle (%) before test/film Example(nm) (degree) (degree) abrasion test peeling 3 30 107 8 11.1 peeling 430 107 7  8.1 peeling

INDUSTRIAL APPLICABILITY

As explained above, by providing a primary oxide film as a compositeoxide film with two or more components including SiO₂ and at least oneselected from among MgO, CaO, SrO and B₂O₃ in a water-repellentfilm-coated article having an integrally formed primary oxide layer anda water-repellent layer by a single coating treatment according to thepresent invention, it is possible to drastically improve the hardness ofthe water-repellent film with the integrally formed primary layer andwater-repellent layer. According to the invention there is no need forhigh-temperature sintering after formation of the water-repellent film,and therefore large-sized equipment is not required so that preparationcosts may be reduced.

Moreover, since a silane compound including water-repellent groups suchas alkyl groups or fluoroalkyl groups is added to the water-repellentcoating solution, it is possible to form the primary oxide layer andwater-repellent layer by application of one type of solution, thusallowing better productivity.

In addition, since the water-repellent groups are naturally orientedduring film formation according to the invention, it is possible to forma water-repellent layer with satisfactory orientation. Thewater-repellent articles of the invention therefore have very excellentwater droplet roll-over properties and high abrasion resistance.

What is claimed is:
 1. A water-repellent film-coated article comprising:a substrate and a water-repellent film, wherein the water-repellent filmis composed of: silica, which is derived from a silane bearing fourhydrolyzable groups, at 70-99 mole percent (based on SiO₂); at least onemetal oxide selected from the group consisting of magnesium oxide,calcium oxide, strontium oxide, and boron oxide, at a total of 1-30 molepercent (based on MgO, CaO, SrO, and BO_(3/2)); and a water-repellentgroup at 0.01-20 wt %; wherein said water-repellent film is coated onthe outer-most surface of the substrate.
 2. A water-repellentfilm-coated article according to claim 1, wherein said water-repellentfilm further contains at least one metal oxide selected from the groupconsisting of zirconium oxide, aluminum oxide, gallium oxide, indiumoxide, scandium oxide, yttrium oxide, lanthanum oxide, cerium oxide,cobalt oxide, iron oxide, nickel oxide, copper oxide and zinc oxide at0.5-5 mole percent (based on ZrO₂, AlO_(3/2), GaO_(3/2), InO_(3/2),ScO_(3/2), YO_(3/2), LaO_(3/2), CeO_(3/2), CoO, FeO_(3/2), NiO₂, CuO andZnO).
 3. A water-repellent film-coated article according to claim 1,wherein said water-repellent film contains silica at 70-98 mole percent(based on SiO₂), magnesium oxide and/or calcium oxide at 1-29 molepercent (based on MgO and CaO), boron oxide and/or zirconium oxide at1-29 mole percent (based on BO_(3/2) and ZrO₂) and a water-repellentgroup at 0.01-20 wt %.
 4. A water-repellent film-coated articleaccording to claim 3, wherein said water-repellent film further containsat least one metal oxide selected from the group consisting of aluminumoxide, gallium oxide, indium oxide, scandium oxide, yttrium oxide,lanthanum oxide, cerium oxide, cobalt oxide, iron oxide, nickel oxide,copper oxide and zinc oxide at 0.5-5 mole percent (based on AlO_(3/2),GaO_(3/2), InO_(3/2), ScO_(3/2), YO_(3/2), LaO_(3/2), CeO_(3/2), CoO,FeO_(3/2), NiO₂, CuO and ZnO).
 5. A water-repellent film-coated articleaccording to any one of claims 2, 3, or 4, wherein said water-repellentgroup is an alkyl group or fluoroalkyl group.
 6. A water-repellentfilm-coated article according to of claims 1, 2, 3, or 4, wherein saidsubstrate is a glass plate.
 7. A water-repellent film-coated articlecomprising: a substrate and a water-repellent film consistingessentially of: silica, which is derived from a silane bearing fourhydrolyzable groups, at 70-99 mole percent (based on SiO₂); at least onemetal oxide selected from the group consisting of magnesium oxide,calcium oxide, strontium oxide, and boron oxide, at a total of 1-30 molepercent (based on MgO, CaO, SrO, and BO_(3/2)); at least one metal oxideselected from the group consisting of zirconium oxide, aluminum oxide,gallium oxide, indium oxide, scandium oxide, yttrium oxide, lanthanumoxide, cerium oxide, cobalt oxide, iron oxide, nickel oxide, copperoxide and zinc oxide, at 0-5 mole percent (based on ZrO₂, AlO_(3/2),GaO_(3/2), InO_(3/2), ScO_(3/2), YO_(3/2), LaO_(3/2), CeO_(3/2), CoO,FeO_(3/2), NiO₂, CuO, and ZnO); and a water-repellent group at 0.01-20wt %; wherein said water-repellent film is coated on the outer-mostsurface of the substrate.